What Lies beyond the ebon gates at the end of the cleft in the mountains.

The postern gate leads into a large chamber, some 100’ east-west, 60’ north south with a ceiling 40’ high.
It is illuminated by lanterns hanging from the ceiling that are similar to those encountered on the heated road.
At the eastern end is another large pair of double doors at least 30’ high and 20’ wide.

Beside the western door is a battered wooden box and nearby is a brazier filled with glowing coals. A small table and chairs, dwarfed by the size of the room is near the brazier.

The Companions have solved the riddle that opened the gates but have yet to meet the gatekeepers or the owners of the lands beyond the gates. However they have some uninvited guests at the door.
Gargoyles and harpies rush in, the latter singing a hideous song.
The combination of magical spells and more mundane arrows dealt with the harpies but the gargoyles still threatened bloody destruction.

As Chang and the gargoyle attacked the door portcullises slammed down. The western one completely blocked that exit but the eastern one jammed on the shoulders of the monster. Almost simultaneously small creatures comprised of boulders and gravel emerged from the floor!

After some mighty blows from the martial members of the companions and some bravery from Thanduil the gargoyles were dispatched and the small boulder goblins vanished.

They moved into the chamber beyond the double doors. Here there were a pair of levers, which seemed to operate the portcullises, some arrow slits in the north and south walls and a single door in the east wall.